1. Field of the Invention
This invention relates generally to the field of devices for data entry into a computer system, and relates more particularly to an apparatus and method for inputting data based on an object within a specified field into a computer and using inputted data to move a virtual object on a display screen.
2. Description of the Relevant Art
Typically, devices such as keyboards, joy sticks, mice, and light pens are used to input data into a computer. A function of these input devices is to position a virtual object such as a cursor on the display screen of a computer. Once the cursor is positioned at a desired location, the computer typically will be instructed to perform an operation. The processes of positioning the cursor and selecting the operation are discrete operations, since separate motions are required to perform each operation. With a mouse, for example, cursor positioning is accomplished by moving a mouse along the surface, while selection of the operation is accomplished by pushing keys located either on the mouse or on a separate keyboard. Mastering the operation of such input devices is often difficult because the hand movements required to operate the devices do not correspond to the visual feedback presented by the display screen of the computer. Furthermore, the operator""s hand must be removed from the keyboard positioned on the mouse and then returned to the keyboard.
Glove input devices also have been used to supply data to computers. U.S. patent application Ser. No. 317,107 by Thomas G. Zimmerman et al., and entitled xe2x80x9cComputer Data Entry and Manipulation Apparatus and Methodxe2x80x9d, describes one such glove input device. This glove input device allows the user to control the movement of a virtual object on a video display screen and perform an operation using a single movement of the operator""s hand.
A problem with such a system is that it requires a wire connection between the object and the computer system to sense the operator""s hand movement. The wire adds to the expense of the manufacture of the system, and may become twisted or broken affecting operation.
Another problem with prior glove input systems is the added expense necessary for the object sensing field. The glove system disclosed in U.S. patent application Ser. No. 317,107 uses a low frequency magnetic field such as the 3SPACE(trademark) system available from Polhemus Inc. of Colchester, Vt. to sense object movement. The wireless input control system in U.S. Pat. No. 4,654,648 uses an acoustical field to sense object movement. The creation of these sensing fields increases manufacturing costs of the computer system.
Tracking systems use software to generate the virtual object on the computer screen. The positioning of the virtual object typically uses triangulation to determine object position on the display screen. Using triangulation to determine object position necessitates knowledge of the distance of the object from the receiver, and computation can be complicated by determination of the squares or square root of the object to receiver distance. The present invention uses a simple averaging method of receiver signal strength to determine virtual object positioning on the computer display terminal; no distance calculation is required. Using this simpler averaging method increases computation speed and decreases complexity.
The present invention provides an inexpensive method and apparatus for transmitting data about an object within a defined field and using transmitted data to generate a virtual object on the display screen of a computer. In one embodiment of the present invention the object used to transmit input data is a wireless glove assembly. The tracking and display system uses a radio frequency signal to track the glove positioning, instead of a more expensive low frequency magnetic or acoustical field. Also, a single averaging method is used to determine the object position instead of the more complex triangulation method.
The glove assembly supports a transmitting device which transmits data bursts of gesture information at a radio frequency to four stationary receivers. The received signal is converted to a digital signal and input to a microprocessor control unit. The software used in the microprocessor control unit uses the inputted data to generate a virtual object on the computer display screen. The position of the virtual object is calculated based on the strength of the signal received. The movement of the virtual object on the computer display screen is in the same direction as and is proportional to the object movement.